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Rainbow Electronics MAX861 User Manual

Page 5

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MAX860/MAX861

50mA, Frequency-Selectable,

Switched-Capacitor Voltage Converters

_______________________________________________________________________________________

5

90

70

80

0

0.33

MAX861

OUTPUT CURRENT vs. CAPACITANCE

HIGH-FREQUENCY MODE

MAX860-10

CAPACITANCE (

µ

F)

OUTPUT CURRENT (mA)

4.7

40

20

1

2.2

22

60

10

10

30

50

V

IN

= +4.5V,

V

OUT

= -3.5V

V

IN

= +4.5V, V

OUT

= -4V

V

IN

= +3V, V

OUT

= -2.4V

V

IN

= +3V, V

OUT

= -2.7V

f

OSC

= 250kHz

FC = OUT
LV = GND
INVERTER MODE

80

70

0

0.33

MAX861

OUTPUT CURRENT vs. CAPACITANCE

MEDIUM-FREQUENCY MODE

MAX860-11

CAPACITANCE (

µ

F)

OUTPUT CURRENT (mA)

4.7

40

20

1

2.2

22

60

10

10

30

50

V

IN

= +4.5V,

V

OUT

= -3.5V

V

IN

= +3V,

V

OUT

= -2.4V

V

IN

= +4.5V,

V

OUT

= -4V

V

IN

= +3V, V

OUT

= -2.7V

f

OSC

= 100kHz

FC = GND
LV = GND
INVERTER MODE

______________________________________________________________Pin Description

____________________________Typical Operating Characteristics (continued)

(All curves generated using the inverter circuit shown in the

Typical Operating Circuits

with LV = GND and T

A

= +25°C, unless other-

wise noted. Test results also valid for doubler mode with LV = OUT and T

A

= +25°C. All capacitor values used are those recom-

mended in Table 3, unless otherwise noted. The output resistance curves represent the resistance of the device itself, which is R

O

in

the equation for R

OUT

shown in the

Capacitor Selection

section.)

INVERTER

DOUBLER

Doubled Positive Output

Flying-Capacitor Negative Terminal

Ground

Low-Voltage-Operation Input. Connect to OUT.

Active-Low Shutdown Input. Connect to GND pin if not
used. Connect to OUT to disable the charge pump.

Positive Input Supply

Flying-Capacitor Positive Terminal

Frequency Control, see Table 1

FUNCTION

Positive Input Supply

V

DD

8

Flying-Capacitor Negative Terminal

C1-

4

Negative Output

OUT

5

Low-Voltage-Operation Input. Connect to GND.

LV

6

Active-Low Shutdown Input. Connect to V

DD

if not

used. Connect to GND to disable the charge pump.

S

H

D

N

7

Ground

GND

3

Flying-Capacitor Positive Terminal

C1+

2

Frequency Control, see Table 1

FC

1

NAME

PIN